Extremely Low Resistance Compositions and Methods for Creating Same

ABSTRACT

The invention pertains to creating new extremely low resistance (“ELR”) materials, which may include high temperature superconducting (“HTS”) materials. In some implementations of the invention, an ELR material may be modified by depositing a layer of modifying material unto the ELR material to form a modified ELR material. The modified ELR material has improved operational characteristics over the ELR material alone. Such operational characteristics may include operating at increased temperatures or carrying additional electrical charge or other operational characteristics. In some implementations of the invention, the ELR material is a cuprate-perovskite, such as, but not limited to BSSCO. In some implementations of the invention, the modifying material is a conductive material that bonds easily to oxygen, such as, but not limited to, chromium.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. application Ser. No.12/794,688, entitled “An Extremely Low Resistance Composition andMethods for Creating Same,” filed on Jun. 4, 2010, which is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The invention is generally related to materials with extremely lowresistance (“ELR materials”) at high temperatures, and more particularlyto modifying ELR materials, including various existing high temperaturesuperconducting (“HTS”) materials, to operate at higher temperaturesand/or with increased charge carrying capacity.

BACKGROUND OF THE INVENTION

Ongoing research attempts to achieve new materials with improvedoperational characteristics, for example, reduced electrical resistanceat higher temperatures over that of existing materials, includingsuperconducting materials. Scientists have theorized a possibleexistence of a “perfect conductor,” or a material that operates withextremely low resistance, but that may not necessarily demonstrate allthe conventionally accepted characteristics of a superconductingmaterial.

Notwithstanding their name, conventional high temperaturesuperconducting (“HTS”) materials still operate at very lowtemperatures. In fact, most commonly used HTS materials still requireuse of a cooling system that uses liquids with very low boiling points(e.g., liquid nitrogen). Such cooling systems increase implementationcosts and discourage widespread commercial and consumer use and/orapplication of such materials.

What is needed are improved ELR materials that operate with improvedoperating characteristics over conventional ELR materials.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate various exemplary implementationsof the invention and together with the detailed description serve toexplain various principles and/or aspects of the invention.

FIG. 1 illustrates a crystalline structure of an exemplary ELR materialas viewed from a first perspective.

FIG. 2 illustrates a crystalline structure of an exemplary ELR materialas viewed from a second perspective.

FIG. 3 illustrates a crystalline structure of an exemplary ELR materialas viewed from a second perspective.

FIG. 4 illustrates a single unit cell of an exemplary ELR material.

FIG. 5 illustrates a crystalline structure of an exemplary ELR materialas viewed from a second perspective.

FIG. 6 illustrates a crystalline structure of an exemplary ELR materialas viewed from a second perspective.

FIG. 7 illustrates a crystalline structure of an exemplary ELR materialas viewed from a second perspective.

FIG. 8 illustrates a crystalline structure of an exemplary ELR materialas viewed from a second perspective.

FIG. 9 illustrates a crystalline structure of an exemplary ELR materialas viewed from a second perspective.

FIG. 10 illustrates a modified crystalline structure, according tovarious implementations of the invention, of an ELR material as viewedfrom a second perspective.

FIG. 11 illustrates a modified crystalline structure, according tovarious implementations of the invention, of an ELR material as viewedfrom a first perspective.

FIG. 12 illustrates a crystalline structure of an exemplary ELR materialas viewed from a third perspective.

FIG. 13 illustrates a reference frame useful for describing variousimplementations of the invention.

FIGS. 14A-14G illustrate test results demonstrating various operationalcharacteristics of a modified ELR material.

FIG. 15 illustrates test results for a modified ELR material, namelywith chromium as a modifying material and YBCO as an ELR material.

FIG. 16 illustrates test results for a modified ELR material, namelywith vanadium as a modifying material and YBCO as an ELR material.

FIG. 17 illustrates test results for a modified ELR material, namelywith bismuth as a modifying material and YBCO as an ELR material.

FIG. 18 illustrates test results for a modified ELR material, namelywith copper as a modifying material and YBCO as an ELR material.

FIG. 19 illustrates test results for a modified ELR material, namelywith cobalt as a modifying material and YBCO as an ELR material.

FIG. 20 illustrates test results for a modified ELR material, namelywith titanium as a modifying material and YBCO as an ELR material.

FIGS. 21A-21B illustrate test results for a modified ELR material,namely with chromium as a modifying material and BSCCO as an ELRmaterial.

FIG. 22 illustrates an arrangement of an ELR material and a modifyingmaterial useful for propagating electrical charge according to variousimplementations of the invention.

FIG. 23 illustrates multiple layers of crystalline structures of anexemplary surface-modified ELR material according to variousimplementations of the invention.

FIG. 24 illustrates a c-film of ELR material according to variousimplementations of the invention.

FIG. 25 illustrates a c-film with appropriate surfaces of ELR materialaccording to various implementations of the invention.

FIG. 26 illustrates a c-film with appropriate surfaces of ELR materialaccording to various implementations of the invention.

FIG. 27 illustrates a modifying material layered onto appropriatesurfaces of ELR material according to various implementations of theinvention.

FIG. 28 illustrates a modifying material layered onto appropriatesurfaces of ELR material according to various implementations of theinvention.

FIG. 29 illustrates a c-film with an etched surface includingappropriate surfaces of ELR material according to variousimplementations of the invention.

FIG. 30 illustrates a modifying material layered onto an etched surfaceof a c-film with appropriate surfaces of ELR material according tovarious implementations of the invention.

FIG. 31 illustrates an a-b film, including an optional substrate, withappropriate surfaces of ELR material according to variousimplementations of the invention.

FIG. 32 illustrates a modifying material layered onto appropriatesurfaces of ELR material of an a-b film according to variousimplementations of the invention.

FIG. 33 illustrates various exemplary arrangements of layers of ELRmaterial, modifying material, buffer or insulating layers, and/orsubstrates in accordance with various implementations of the invention.

FIG. 34 illustrates a process for forming a modified ELR materialaccording to various implementations of the invention.

FIG. 35 illustrates an example of additional processing that may beperformed according to various implementations of the invention.

FIG. 36 illustrates a process for forming a modified ELR materialaccording to various implementations of the invention.

SUMMARY OF THE INVENTION

Generally speaking, various implementations of the invention relate tonew ELR materials and/or processes for creating new ELR materials. Insome implementations of the invention, existing ELR materials, includingexisting HTS materials, are modified to create modified ELR materialswith improved operating characteristics. These operating characteristicsmay include, but are not limited to, operating in an extremely lowresistance state at increased temperatures, operating with increasedcharge carrying capacity at the same (or higher) temperatures, and/orother improved operating characteristics. With regard to HTS materials,these operating characteristics may correspondingly include, but are notlimited to, operating in a superconducting state at increasedtemperatures, operating with increased charge carrying capacity at thesame (or higher) temperatures, and/or other improved operatingcharacteristics.

In some implementations, a modifying material is layered onto an ELRmaterial to form a modified ELR material that operates at a highertemperature than that of the ELR material without a modifying material.Exemplary ELR materials may be selected from a family of HTS materialsknown as cuprate-perovskite ceramic materials. In some implementationsof the invention, modifying material may be a conductive material. Insome implementations of the invention, modifying material may be amaterial with high oxygen affinity (i.e., a material that bonds easilywith oxygen) (“oxygen bonding material”). In some implementations of theinvention, modifying material may be a conductive material that bondseasily with oxygen (“oxygen bonding conductive materials”). Such oxygenbonding conductive materials may include, but are not limited to:chromium, copper, bismuth, cobalt, vanadium, and titanium. Such oxygenbonding conductive materials may also include, but are not limited to:rhodium or beryllium. Other modifying materials may include gallium orselenium. Other modifying materials may include silver.

In some implementations of the invention, a composition comprises an ELRmaterial and a modifying material bonded to the ELR material.

In some implementations of the invention, a composition comprises anextremely low resistance material, and a modifying material bonded tothe extremely low resistance material, where the composition hasimproved operating characteristics over the extremely low resistancematerial.

In some implementations of the invention, a composition comprises anextremely low resistance material, and a modifying material bonded tothe extremely low resistance material such that the composition operatesin an ELR state at a temperature greater than that of the extremely lowresistance material alone or without the modifying material.

In some implementations of the invention, a method comprises bonding amodifying material to an extremely low resistance material to form amodified extremely low resistance material, where the modified extremelylow resistance material operates at a temperature greater than that ofthe extremely low resistance material alone or without the modifyingmaterial.

In some implementations of the invention, a method for creating anextremely low resistance material comprises depositing a modifyingmaterial onto an initial extremely low resistance material therebycreating the extremely low resistance material, wherein the extremelylow resistance material has improved operating characteristics over theinitial extremely low resistance material alone or without the modifyingmaterial.

In some implementations of the invention, a method comprises bonding amodifying material to a superconducting material to form a modifiedsuperconducting material such that the modified superconducting materialoperates in superconducting state at a temperature greater than that ofthe superconducting material alone or without the modifying material.

In some implementations of the invention, a composition comprises afirst layer comprising an extremely low resistance material, and asecond layer comprising a modifying material, where the second layer isbonded to the first layer. In some implementations of the invention, acomposition comprises a first layer comprising an extremely lowresistance material, a second layer comprising a modifying material,where the second layer is bonded to the first layer, a third layercomprising the extremely low resistance material, and a fourth layer ofthe modifying material, where the third layer is bonded to the fourthlayer. In some implementations of the invention, the second layer isdeposited onto the first layer. In some implementations of theinvention, the first layer is deposited onto the second layer. In someimplementations of the invention, the extremely low resistance materialof the first layer is formed on the second layer. In someimplementations of the invention, the first layer has a thickness of atleast a single crystalline unit cell of the extremely low resistancematerial. In some implementations of the invention, the first layer hasa thickness of several crystalline unit cells of the extremely lowresistance material. In some implementations of the invention, thesecond layer has a thickness of at least a single atom of the modifyingmaterial. In some implementations of the invention, the second layer hasa thickness of several atoms of the modifying material.

In some implementations of the invention, a composition comprises afirst layer comprising BSSCO, and a second layer comprising a modifyingmaterial, wherein the modifying material of the second layer is bondedto the BSSCO of the first layer, wherein the modifying material is anelement selected as any one or more of the group consisting of chromium,copper, bismuth, cobalt, vanadium, titanium, rhodium, beryllium,gallium, selenium, and silver. In some implementations of the invention,the modifying material of the second layer is bonded to a face of theBSSCO of the first layer, where the face is not substantiallyperpendicular to a c-axis of the BSSCO. In some implementations of theinvention, the modifying material of the second layer is bonded to aface of the BSSCO of the first layer, where the face is substantiallyperpendicular to any line in an “a-b” face of the BSSCO. In someimplementations of the invention, the modifying material of the secondlayer is bonded to a face of the BSSCO of the first layer, where theface is substantially perpendicular to a b-axis of the BSSCO. In someimplementations of the invention, the modifying material of the secondlayer is bonded to a face of the BSSCO of the first layer, where theface is substantially perpendicular to an a-axis of the BSSCO. In someimplementations of the invention, the modifying material of the secondlayer is bonded to a face of the BSSCO of the first layer, where theface is substantially parallel to the c-axis.

In any of the aforementioned or following implementations of theinvention, the ELR material comprises a HTS material. In any of theaforementioned or following implementations of the invention, the ELRmaterial comprises an HTS perovskite material. In any of theaforementioned or following implementations of the invention, the HTSperovskite material may be selected from the groups generically referredto as LaBaCuO, LSCO, YBCO, BSCCO, TBCCO, HgBa₂Ca₂Cu₃O_(x), or other HTSperovskite materials. In any of the aforementioned or followingimplementations of the invention, the modifying materials may be aconductive material that bonds easily with oxygen. In any of theaforementioned or following implementations of the invention, themodifying materials may be any one or combination of chromium, copper,bismuth, cobalt, vanadium, titanium, rhodium, beryllium, gallium,selenium, and/or silver. In any of the aforementioned or followingimplementations of the invention, various combinations of the ELRmaterials and the modifying materials may be used. In any of theaforementioned or following implementations of the invention, the ELRmaterial is BSSCO and the modifying material is chromium.

In any of the aforementioned or following implementations of theinvention, the composition operates at a higher temperature than theextremely low resistance material alone or without the modifyingmaterial. In any of the aforementioned or following implementations ofthe invention, the composition demonstrates extremely low resistance ata higher temperature than that of the extremely low resistance materialalone or without the modifying material. In any of the aforementioned orfollowing implementations of the invention, the composition transitionsfrom a non-ELR state to an ELR state at a temperature higher than thatof the extremely low resistance material alone or without the modifyingmaterial. In any of the aforementioned or following implementations ofthe invention, the composition has a transition temperature greater thanthat of the extremely low resistance material alone or without themodifying material. In any of the aforementioned or followingimplementations of the invention, the composition carries a greateramount of current in an ELR state than that carried by the extremely lowresistance material alone or without the modifying material.

In any of the aforementioned or following implementations, thecomposition operates in an extremely low resistance state at a highertemperature than the extremely low resistance material alone or withoutthe modifying material. In any of the aforementioned or followingimplementations, the composition operates in an extremely low resistancestate at temperatures greater than one or more of the followingtemperatures: 100K, 110K, 120K, 130K, 140K, 150K, 160K, 170K, 180K,190K, 200K, 210K, 220K, 230K, 240K, 250K, 260K, 270K, 280K, 290K, 300K,or 310K.

In any of the aforementioned or following implementations where the ELRmaterial is BSSCO, the composition has improved operatingcharacteristics over those of BSSCO alone or without the modifyingmaterial. In any of the aforementioned or following implementationswhere the ELR material is BSSCO, the composition operates at a highertemperature than that of BSSCO alone or without the modifying material.In any of the aforementioned or following implementations where the ELRmaterial is BSSCO, the composition demonstrates extremely low resistanceat a higher temperature than that of BSSCO alone or without themodifying material. In any of the aforementioned or followingimplementations where the ELR material is BSSCO, the compositiontransitions from a non-ELR state to an ELR state at a temperature higherthan that of BSSCO alone or without the modifying material. In any ofthe aforementioned or following implementations where the ELR materialis BSSCO, the composition has a transition temperature greater than thatof BSSCO alone or without the modifying material. In any of theaforementioned or following implementations where the ELR material isBSSCO, the composition carries a greater amount of current in an ELRstate than that carried by BSSCO in its ELR state alone or without themodifying material.

In some implementations of the invention, a product or composition isproduced by any of the aforementioned methods or processes.

DETAILED DESCRIPTION

Various features, advantages, and implementations of the invention maybe set forth or be apparent from consideration of the following detaileddescription, the drawings, and the claims. It is to be understood thatthe detailed description and the drawings are exemplary and intended toprovide further explanation without limiting the scope of the inventionexcept as set forth in the claims.

For purposes of this description, extremely low resistance (“ELR”)materials may include: superconducting materials, including, but notlimited to, HTS materials; perfectly conducting materials (e.g., perfectconductors); and other conductive materials with extremely lowresistance. For purposes of this description, operating characteristicswith regard to ELR materials and/or various implementations of theinvention may include, but are not limited to, a resistance of the ELRmaterial in its ELR state (for example, with regard to superconductors,a superconducting state), a transition temperature of the ELR materialto its ELR state, a charge propagating capacity of the ELR material inits ELR state, one or more magnetic properties of the ELR material, oneor more mechanical properties of the ELR material, and/or otheroperating characteristics of the ELR material. Further, for purposes ofthis description, improved operating characteristics may include, butare not limited to, operating in an ELR state (including, for example, asuperconducting state) at higher temperatures, operating with increasedcharge propagating capacity at the same (or higher) temperatures,operating with improved magnetic properties, operating with improvedmechanical properties, and/or other improved operating characteristics.

For purposes of this description, “extremely low resistance” isresistance similar in magnitude to the flux flow resistance of Type IIsuperconducting materials in their superconducting state, and maygenerally be expressed in terms of resistivity in a range of zero Ohm-cmto one fiftieth (1/50) of the resistivity of substantially pure copperat 293K. For example, as used herein, substantially pure copper is99.999% copper. In various implementations of the invention, portions ofELR materials have a resistivity in a range of zero Ohm-cm to 3.36×10⁻⁸Ohm-cm.

As generally understood, the transition temperature is a temperaturebelow which the ELR material “operates” or exhibits (or beginsexhibiting) extremely low resistance, and/or other phenomenon associatedwith ELR materials. When operating with extremely low resistance, theELR material is referred to as being in an ELR state. At temperaturesabove the transition temperature, the ELR material ceases to exhibitextremely low resistance and the ELR material is referred to as being inits non-ELR state. In other words, the transition temperaturecorresponds to a temperature at which the ELR material changes betweenits non-ELR state and its ELR state. As would be appreciated, for someELR materials, the transition temperature may be a range of temperaturesover which the ELR material changes between its non-ELR state and itsELR state. As would also be appreciated, the ELR material may havehysteresis in its transition temperature with one transition temperatureas the ELR material warms and another transition temperature as the ELRmaterial cools.

FIG. 13 illustrates a reference frame 1300 which may be used to describevarious implementations of the invention. Reference frame 1300 includesa set of axes referred to as an a-axis, a b-axis, and a c-axis. Forpurposes of this description: reference to the a-axis includes thea-axis and any other axis parallel thereto; reference to the b-axisincludes the b-axis and any other axis parallel thereto; and referenceto the c-axis includes the c-axis and any other axis parallel thereto.Various pairs of the axes form a set of planes in reference frame 1300referred to as an a-plane, a b-plane, and a c-plane, where: the a-planeis formed by the b-axis and the c-axis and is perpendicular to thea-axis; the b-plane is formed by the a-axis and the c-axis and isperpendicular to the b-axis; and the c-plane is formed by the a-axis andthe b-axis and is perpendicular to the c-axis. For purposes of thisdescription: reference to the a-plane includes the a-plane and any planeparallel thereto; reference to the b-plane includes the b-plane and anyplane parallel thereto; and reference to the c-plane includes thec-plane and any plane parallel thereto. Further, with regard to various“faces” or “surfaces” of the crystalline structures described herein, aface parallel to the a-plane may sometimes be referred to as a “b-c”face; a face parallel to the b-plane may sometimes be referred to as an“a-c” face; and a face parallel to the c-plane may sometimes be referredto as a “a-b” face.

FIG. 1 illustrates a crystalline structure 100 of an exemplary ELRmaterial as viewed from a first perspective, namely, a perspectiveperpendicular to an “a-b” face of crystalline structure 100 and parallelto the c-axis thereof. FIG. 2 illustrates crystalline structure 100 asviewed from a second perspective, namely, a perspective perpendicular toa “b-c” face of crystalline structure 100 and parallel to the a-axisthereof. For purposes of this description, the exemplary ELR materialillustrated in FIG. 1 and FIG. 2 is generally representative of variousELR materials. In some implementations of the invention, the exemplaryELR material may be a representative of a family of superconductingmaterials referred to as mixed-valence copper-oxide perovskites. Themixed-valence copper-oxide perovskite materials include, but are notlimited to, LaBaCuO_(x), LSCO (e.g., La_(2-x)Sr_(x)CuO₄, etc.), YBCO(e.g., YBa₂Cu₃O₇, etc.), BSCCO (e.g., Bi₂Sr₂Ca₂Cu₃O₁₀, etc.), TBCCO(e.g., TI₂Ba₂Ca₂Cu₃O₁₀ or TI_(m)Ba₂Ca_(n-1)Cu_(n)O_(2n+m+2+δ)),HgBa₂Ca₂Cu₃O_(x), and other mixed-valence copper-oxide perovskitematerials. The other mixed-valence copper-oxide perovskite materials mayinclude, but are not limited to, various substitutions of the cations aswould be appreciated. As would also be appreciated, the aforementionednamed mixed-valence copper-oxide perovskite materials may refer togeneric classes of materials in which many different formulations exist.In some implementations of the invention, the exemplary ELR materialsmay include an HTS material outside of the family of mixed-valencecopper-oxide perovskite materials (“non-perovskite materials”). Suchnon-perovskite materials may include, but are not limited to, ironpnictides, magnesium diboride (MgB₂), and other non-perovskites. In someimplementations of the invention, the exemplary ELR materials may beother superconducting materials.

Many ELR materials have a structure similar to (though not necessarilyidentical to) that of crystalline structure 100 with different atoms,combinations of atoms, and/or lattice arrangements as would beappreciated. As illustrated in FIG. 2, crystalline structure 100 isdepicted with two complete unit cells of the exemplary ELR material,with one unit cell above reference line 110 and one unit cell belowreference line 110. FIG. 4 illustrates a single unit cell 400 of theexemplary ELR material.

Generally speaking and as would be appreciated, a unit cell 400 of theexemplary ELR material includes six “faces”: two “a-b” faces that areparallel to the c-plane; two “a-c” faces that are parallel to theb-plane; and two “b-c” faces that are parallel to the a-plane (see,e.g., FIG. 13). As would also be appreciated, a “surface” of ELRmaterial in the macro sense may be comprised of multiple unit cells 400(e.g., hundreds, thousands or more). Reference in this description to a“surface” or “face” of the ELR material being parallel to a particularplane (e.g., the a-plane, the b-plane or the c-plane) indicates that thesurface is formed predominately (i.e., a vast majority) of faces of unitcell 400 that are substantially parallel to the particular plane.Furthermore, reference in this description to a “surface” or “face” ofthe ELR material being parallel to planes other than the a-plane, theb-plane, or the c-plane (e.g., an ab-plane as described below, etc.)indicates that the surface is formed from some mixture of faces of unitcell 400 that, in the aggregate macro sense, form a surfacesubstantially parallel to such other planes.

Studies indicate that some ELR materials demonstrate an anisotropic(i.e., directional) dependence of the resistance phenomenon. In otherwords, resistance at a given temperature and current density dependsupon a direction in relation to crystalline structure 100. For example,in their ELR state, some ELR materials can carry significantly morecurrent, at extremely low resistance, in the direction of the a-axisand/or in the direction of the b-axis than such materials do in thedirection of the c-axis. As would be appreciated, various ELR materialsexhibit anisotropy in various performance phenomenon, including theresistance phenomenon, in directions other than, in addition to, or ascombinations of those described above. For purposes of this description,reference to a material that tends to exhibit the resistance phenomenon(and similar language) in a first direction indicates that the materialsupports such phenomenon in the first direction; and reference to amaterial that tends not to exhibit the resistance phenomenon (andsimilar language) in a second direction indicates that the material doesnot support such phenomenon in the second direction or does so in areduced manner from other directions.

With reference to FIG. 2, conventional understanding of known ELRmaterials has thus far failed to appreciate an aperture 210 formedwithin crystalline structure 100 by a plurality of aperture atoms 250 asbeing responsible for the resistance phenomenon. (See e.g., FIG. 4,where an aperture is not readily apparent in a depiction of single unitcell 400.) In some sense, aperture atoms 250 may be viewed as forming adiscrete atomic “boundary” or “perimeter” around aperture 210. In someimplementations of the invention and as illustrated in FIG. 2, aperture210 appears between a first portion 220 and a second portion 230 ofcrystalline structure 100 although in some implementations of theinvention, aperture 210 may appear in other portions of various othercrystalline structures. Aperture 210 is illustrated in FIG. 2 based ondepictions of atoms as simple “spheres;” it would be appreciated thatsuch apertures are related to and shaped by, among other things,electrons and their associated electron densities (not otherwiseillustrated) of various atoms in crystalline structure 100, includingaperture atoms 250.

According to various aspects of the invention, aperture 210 facilitatespropagation of electrical charge through crystalline structure 100 andwhen aperture 210 facilitates propagation of electrical charge throughcrystalline structure 100, ELR material operates in its ELR state. Forpurposes of this description, “propagates,” “propagating,” and/or“facilitating propagation” (along with their respective forms) generallyrefer to “conducts,” “conducting” and/or “facilitating conduction” andtheir respective forms; “transports,” “transporting” and/or“facilitating transport” and their respective forms; “guides,” “guiding”and/or “facilitating guidance” and their respective forms; and/or“carry,” “carrying” and/or “facilitating carrying” and their respectiveforms. For purposes of this description, electrical charge may includepositive charge or negative charge, and/or pairs or other groupings ofsuch charges; further, such charge may propagate through crystallinestructure 100 in the form of one or more particles or in the form of oneor more waves or wave packets.

In some implementations of the invention, propagation of electricalcharge through crystalline structure 100 may be in a manner analogous tothat of a waveguide. In some implementations of the invention, aperture210 may be a waveguide with regard to propagating electrical chargethrough crystalline structure 100. Waveguides and their operation aregenerally well understood. In particular, walls surrounding an interiorof the waveguide may correspond to the boundary or perimeter of apertureatoms 250 around aperture 210. One aspect relevant to an operation of awaveguide is its cross-section. At the atomic level, aperture 210 and/orits cross-section may change substantially with changes in temperatureof the ELR material. For example, in some implementations of theinvention, changes in temperature of the ELR material may cause changesin aperture 210, which in turn may cause the ELR material to transitionbetween its ELR state to its non-ELR state. For example, as temperatureof the ELR material increases, aperture 210 may restrict or impedepropagation of electrical charge through crystalline structure 100 andthe corresponding ELR material may transition from its ELR state to itsnon-ELR state. Likewise, for example, as temperature of the ELR materialdecreases, aperture 210 may facilitate (as opposed to restrict orimpede) propagation of electrical charge through crystalline structure100 and the corresponding ELR material may transition from its non-ELRstate to its ELR state.

Apertures, such as aperture 210 in FIG. 2, exist in various ELRmaterials, such as, but not limited to, various ELR materialsillustrated in FIG. 3 and FIGS. 5-9, etc., and described below. Asillustrated, such apertures are intrinsic to the crystalline structureof some or all the ELR materials. Various forms, shapes, sizes, andnumbers of apertures 210 exist in ELR materials depending on the preciseconfiguration of the crystalline structure, composition of atoms, andarrangement of atoms within the crystalline structure of the ELRmaterial as would be appreciated in light of this description.

The presence and absence of apertures 210 that extend in the directionof various axes through the crystalline structures 100 of various ELRmaterials is consistent with the anisotropic dependence demonstrated bysuch ELR materials. For example, ELR material 360, which is illustratedin FIG. 3, FIG. 11, and FIG. 12, corresponds to YBCO-123, which exhibitsthe resistance phenomenon in the direction of the a-axis and the b-axis,but tends not to exhibit the resistance phenomenon in the direction ofthe c-axis. Consistent with the anisotropic dependence of the resistancephenomenon demonstrated by YBCO-123, FIG. 3 illustrates that apertures310 extend through crystalline structure 300 in the direction of thea-axis; FIG. 12 illustrates that apertures 310 and apertures 1210 extendthrough crystalline structure 300 in the direction of the b-axis; andFIG. 11 illustrates that no suitable apertures extend throughcrystalline structure 300 in the direction of the c-axis.

Aperture 210 and/or its cross-section may be dependent upon variousatomic characteristics of aperture atoms 250 and/or “non-aperture atoms”(i.e., atoms in crystalline structure 100 other than aperture atoms250). Such atomic characteristics include, but are not limited to,atomic size, atomic weight, numbers of electrons, electron structure,number of bonds, types of bonds, differing bonds, multiple bonds, bondlengths, bond strengths, bond angles between aperture atoms, bond anglesbetween aperture atoms and non-aperture atoms, and/or isotope number.Aperture atoms 250 and non-aperture atomrs may be selected based ontheir corresponding atomic characteristics to optimize aperture 210 interms of its size, shape, rigidity, and modes of vibration (in terms ofamplitude, frequency, and direction) in relation to crystallinestructure and/or atoms therein.

According to various implementations of the invention, changes in aphysical structure of aperture 210, including changes to a shape and/orsize of its cross-section and/or changes to the shape or size ofaperture atoms 205, may have an impact on the resistance phenomenon. Forexample, as temperature of crystalline structure 100 increases, thecross-section of aperture 210 may be changed due to vibration of variousatoms within crystalline structure 100 as well as changes in energystates, or occupancy thereof, of the atoms in crystalline structure 100.Physical flexure, tension or compression of crystalline structure 100may also affect the positions of various atoms within crystallinestructure 100 and therefore the cross-section of aperture 210. Magneticfields imposed on crystalline structure 100 may also affect thepositions of various atoms within crystalline structure 100 andtherefore the cross-section of aperture 210.

Phonons correspond to various modes of vibration within crystallinestructure 100. Phonons in crystalline structure 100 may interact withelectrical charge propagated through crystalline structure 100. Moreparticularly, phonons in crystalline structure 100 may cause atoms incrystalline structure 100 (e.g., aperture atoms 250, non-aperture atoms,etc.) to interact with electrical charge propagated through crystallinestructure 100. Higher temperatures result in higher phonon amplitude andmay result in increased interaction among phonons, atoms in crystallinestructure 100, and such electrical charge. Various implementations ofthe invention may minimize, reduce, or otherwise modify such interactionamong phonons, atoms in crystalline structure 100, and such electricalcharge within crystalline structure 100.

FIG. 3 illustrates a crystalline structure 300 of an exemplary ELRmaterial 360 from a second perspective. Exemplary ELR material 360 is asuperconducting material commonly referred to as “YBCO” which, incertain formulations, has a transition temperature of approximately 90K.In particular, exemplary ELR material 360 depicted in FIG. 3 isYBCO-123. Crystalline structure 300 of exemplary ELR material 360includes various atoms of yttrium (“Y”), barium (“Ba”), copper (“Cu”)and oxygen (“O”). As illustrated in FIG. 3, an aperture 310 is formedwithin crystalline structure 300 by aperture atoms 350, namely atoms ofyttrium, copper, and oxygen. A cross-sectional distance between theyttrium aperture atoms in aperture 310 is approximately 0.389 nm, across-sectional distance between the oxygen aperture atoms in aperture310 is approximately 0.285 nm, and a cross-sectional distance betweenthe copper aperture atoms in aperture 310 is approximately 0.339 nm.

FIG. 12 illustrates crystalline structure 300 of exemplary ELR material360 from a third perspective. Similar to that described above withregard to FIG. 3, exemplary ELR material 360 is YBCO-123, and aperture310 is formed within crystalline structure 300 by aperture atoms 350,namely atoms of yttrium, copper, and oxygen. In this orientation, across-sectional distance between the yttrium aperture atoms in aperture310 is approximately 0.382 nm, a cross-sectional distance between theoxygen aperture atoms in aperture 310 is approximately 0.288 nm, and across-sectional distance between the copper aperture atoms in aperture310 is approximately 0.339 nm. In this orientation, in addition toaperture 310, crystalline structure 300 of exemplary ELR material 360includes an aperture 1210. Aperture 1210 occurs in the direction of theb-axis of crystalline structure 300. More particularly, aperture 1210occurs between individual unit cells of exemplary ELR material 360 incrystalline structure 300. Aperture 1210 is formed within crystallinestructure 300 by aperture atoms 1250, namely atoms of barium, copper andoxygen. A cross-sectional distance between the barium aperture atoms1250 in aperture 1210 is approximately 0.430 nm, a cross-sectionaldistance between the oxygen aperture atoms 1250 in aperture 1210 isapproximately 0.382 nm, and a cross-sectional distance between thecopper aperture atoms 1250 in aperture 1210 is approximately 0.382 nm.In some implementations of the invention, aperture 1210 operates in amanner similar to that described herein with regard to aperture 310. Forpurposes of this description, aperture 310 in YBCO may be referred to asan “yttrium aperture,” whereas aperture 1210 in YBCO may be referred toas a “barium aperture,” based on the compositions of their respectiveaperture atoms 350, 1250.

FIG. 5 illustrates a crystalline structure 500 of an exemplary ELRmaterial 560 as viewed from the second perspective. Exemplary ELRmaterial 560 is an HTS material commonly referred to as “HgBa₂CuO₄”which has a transition temperature of approximately 94K. Crystallinestructure 500 of exemplary ELR material 560 includes various atoms ofmercury (“Hg”), barium (“Ba”), copper (“Cu”), and oxygen (“O”). Asillustrated in FIG. 5, an aperture 510 is formed within crystallinestructure 500 by aperture atoms which comprise atoms of barium, copper,and oxygen.

FIG. 6 illustrates a crystalline structure 600 of an exemplary ELRmaterial 660 as viewed from the second perspective. Exemplary ELRmaterial 660 is an HTS material commonly referred to as“TI₂Ca₂Ba₂Cu₃O₁₀” which has a transition temperature of approximately128K. Crystalline structure 600 of exemplary ELR material 660 includesvarious atoms of thallium (“TI”), calcium (“Ca”), barium (“Ba”), copper(“Cu”), and oxygen (“O”). As illustrated in FIG. 6, an aperture 610 isformed within crystalline structure 600 by aperture atoms which compriseatoms of calcium, barium, copper and oxygen. As also illustrated in FIG.6, a secondary aperture 620 may also be formed within crystallinestructure 600 by secondary aperture atoms which comprise atoms ofcalcium, copper and oxygen. Secondary apertures 620 may operate in amanner similar to that of apertures 610.

FIG. 7 illustrates a crystalline structure 700 of an exemplary ELRmaterial 760 as viewed from the second perspective. Exemplary ELRmaterial 760 is an HTS material commonly referred to as “La₂CuO₄” whichhas a transition temperature of approximately 39K. Crystalline structure700 of exemplary ELR material 760 includes various atoms of lanthanum(“La”), copper (“Cu”), and oxygen (“O”). As illustrated in FIG. 7, anaperture 710 is formed within crystalline structure 700 by apertureatoms which comprise atoms of lanthanum and oxygen.

FIG. 8 illustrates a crystalline structure 800 of an exemplary ELRmaterial 860 as viewed from the second perspective. Exemplary ELRmaterial 860 is an HTS material commonly referred to as“As₂Ba_(0.34)Fe₂K_(0.66)” which has a transition temperature ofapproximately 38K. Exemplary ELR material 860 is representative of afamily of ELR materials sometimes referred to as “iron pnictides.”Crystalline structure 800 of exemplary ELR material 860 includes variousatoms of arsenic (“As”), barium (“Ba”), iron (“Fe”), and potassium(“K”). As illustrated in FIG. 8, an aperture 810 is formed withincrystalline structure 800 by aperture atoms which comprise atoms ofpotassium and arsenic.

FIG. 9 illustrates a crystalline structure 900 of an exemplary ELRmaterial 960 as viewed from the second perspective. Exemplary ELRmaterial 960 is an HTS material commonly referred to as “MgB₂” which hasa transition temperature of approximately 39K. Crystalline structure 900of exemplary ELR material 960 includes various atoms of magnesium (“Mg”)and boron (“B”). As illustrated in FIG. 9, an aperture 910 is formedwithin crystalline structure 900 by aperture atoms which comprise atomsof magnesium and boron.

The foregoing exemplary ELR materials illustrated in FIG. 3, FIGS. 5-9,and FIG. 12 each demonstrate the presence of various apertures withinsuch materials. Various other ELR materials have similar apertures. Onceattributed to the resistance phenomenon, apertures and theircorresponding crystalline structures may be exploited to improveoperating characteristics of existing ELR materials, to derive improvedELR materials from existing ELR materials, and/or to design andformulate new ELR materials. For convenience of description, ELRmaterial 360 (and its attendant characteristics and structures)henceforth generally refers to various ELR materials, including, but notlimited to, ELR material 560, ELR material 660, ELR material 760, andother ELR materials illustrated in the drawings, not just that ELRmaterial illustrated and described with reference to FIG. 3.

According to various implementations of the invention, the crystallinestructure of various known ELR materials may be modified such that themodified ELR material operates with improved operating characteristicsover the known ELR material. In some implementations of the invention,this may also be accomplished, for example, by layering a material overcrystalline structure 100 such that atoms of the material span aperture210 by forming one or more bonds between first portion 220 and secondportion 230 as would be appreciated. This particular modification oflayering a material over crystalline structure 100 is described infurther detail below in connection with various experimental testresults.

FIG. 10 illustrates a modified crystalline structure 1010 of a modifiedELR material 1060 as viewed from the second perspective in accordancewith various implementations of the invention. FIG. 11 illustratesmodified crystalline structure 1010 of modified ELR material 1060 asviewed from the first perspective in accordance with variousimplementations of the invention. ELR material 360 (e.g., for example,as illustrated in FIG. 3 and elsewhere) is modified to form modified ELRmaterial 1060. Modifying material 1020 forms bonds with atoms ofcrystalline structure 300 (of FIG. 3) of ELR material 360 to formmodified crystalline structure 1010 of modified ELR material 1060 asillustrated in FIG. 11. As illustrated, modifying material 1020 bridgesa gap between first portion 320 and second portion 330 thereby changing,among other things, vibration characteristics of modified crystallinestructure 1010, particularly in the region of aperture 310. In doing so,modifying material 1020 maintains aperture 310 at higher temperatures.Accordingly, in some implementations of the invention, modifyingmaterial 1020 is specifically selected to fit in and bond withappropriate atoms in crystalline structure 300.

In some implementations of the invention and as illustrated in FIG. 10,modifying material 1020 is bonded to a face of crystalline structure 300that is parallel to the b-plane (e.g., an “a-c” face). In suchimplementations where modifying material 1020 is bonded to the “a-c”face, apertures 310 extending in the direction of the a-axis and withcross-sections lying in the a-plane are maintained. In suchimplementations, charge carriers flow through aperture 310 in thedirection of the a-axis.

In some implementations of the invention, modifying material 1020 isbonded to a face of crystalline structure 300 that is parallel to thea-plane (e.g., a “b-c” face). In such implementations where modifyingmaterial 1020 is bonded to the “b-c” face, apertures 310 extending inthe direction of the b-axis and with cross-sections lying in the b-planeare maintained. In such implementations, charge carriers flow throughaperture 310 in the direction of the b-axis.

Various implementations of the invention include layering a particularsurface of ELR material 360 with modifying material 1020 (i.e.,modifying the particular surface of ELR material 360 with the modifyingmaterial 1020). As would be recognized from this description, referenceto “modifying a surface” of ELR material 360, ultimately includesmodifying a face (and in some cases more that one face) of one or moreunit cells 400 of ELR material 360. In other words, modifying material1020 actually bonds to atoms in unit cell 400 of ELR material 360.

For example, modifying a surface of ELR material 360 parallel to thea-plane includes modifying “b-c” faces of unit cells 400. Likewise,modifying a surface of ELR material 360 parallel to the b-plane includesmodifying “a-c” faces of unit cells 400. In some implementations of theinvention, modifying material 1020 is bonded to a surface of ELRmaterial 360 that is substantially parallel to any plane that isparallel to the c-axis. For purposes of this description, planes thatare parallel to the c-axis are referred to generally as ab-planes, andas would be appreciated, include the a-plane and the b-plane. As wouldbe appreciated, a surface of ELR material 360 parallel to the ab-planeis formed from some mixture of “a-c” faces and “b-c” faces of unit cells400. In such implementations where modifying material 1020 is bonded toa surface parallel to an ab-plane, apertures 310 extending in thedirection of the a-axis and apertures 310 extending in the direction ofthe b-axis are maintained.

In some implementations of the invention, modifying material 1020 may bea conductive material. In some implementations of the invention,modifying material 1020 may a material with high oxygen affinity (i.e.,a material that bonds easily with oxygen) (“oxygen bonding material”).In some implementations of the invention, modifying material 1020 may bea conductive material that bonds easily with oxygen (“oxygen bondingconductive materials”). Such oxygen bonding conductive materials mayinclude, but are not limited to: chromium, copper, bismuth, cobalt,vanadium, and titanium. Such oxygen bonding conductive materials mayalso include, but are not limited to: rhodium or beryllium. Othermodifying materials may include gallium or selenium. Other modifyingmaterials may include silver. Still other modifying materials may beused.

In some implementations of the invention, oxides of modifying material1020 may form during various operations associated with modifying ELRmaterial 360 with modifying material 1020. Accordingly, in someimplementations of the invention, modifying material 1020 may include asubstantially pure form of modifying material 1020 and/or various oxidesof modifying material 1020. In other words, in some implementations ofthe invention, ELR material 360 is modified with modifying material 1020and/or various oxides of modifying material 1020. By way of example, butnot limitation, in some implementations of the invention, modifyingmaterial 1020 may comprise chromium and/or chromium oxide (Cr_(x)O_(y)).

In some implementations of the invention, ELR material 360 may be YBCOand modifying material 1020 may be an oxygen bonding conductivematerial. In some implementations of the invention, ELR material 360 maybe YBCO and modifying material 1020 may be selected from the groupincluding, but not limited to: chromium, copper, bismuth, cobalt,vanadium, titanium, rhodium, or beryllium. In some implementations ofthe invention, ELR material 360 may be YBCO and modifying material 1020may be selected from the group consisting of: chromium, copper, bismuth,cobalt, vanadium, titanium, rhodium, and beryllium. In someimplementations of the invention, ELR material 360 may be YBCO andmodifying material 1020 may be another modifying material.

In some implementations of the invention, various other combinations ofmixed-valence copper-oxide perovskite materials and oxygen bondingconductive materials may be used. For example, in some implementationsof the invention, ELR material 360 corresponds to a mixed-valencecopper-oxide perovskite material commonly referred to as “BSCCO.” BSCCOincludes various atoms of bismuth (“Bi”), strontium (“Sr”), calcium(“Ca”), copper (“Cu”) and oxygen (“O”). By itself, BSCCO has atransition temperature of approximately 100K. In some implementations ofthe invention, ELR material 360 may be BSCCO and modifying material 1020may be an oxygen bonding conductive material. In some implementations ofthe invention, ELR material 360 may be BSCCO and modifying material 1020may be selected from the group including, but not limited to: chromium,copper, bismuth, cobalt, vanadium, titanium, rhodium, or beryllium. Insome implementations of the invention, ELR material 360 may be BSCCO andmodifying material 1020 may be selected from the group consisting of:chromium, copper, bismuth, cobalt, vanadium, titanium, rhodium, andberyllium. In some implementations of the invention, ELR material 360may be BSCCO and modifying material 1020 may be another modifyingmaterial.

In some implementations of the invention, various combinations of otherELR materials and modifying materials may be used. For example, in someimplementations of the invention, ELR material 360 corresponds to aniron pnictide material. Iron pnictides, by themselves, have transitiontemperatures that range from approximately 25-60K. In someimplementations of the invention, ELR material 360 may be an ironpnictide and modifying material 1020 may be an oxygen bonding conductivematerial. In some implementations of the invention, ELR material 360 maybe an iron pnictide and modifying material 1020 may be selected from thegroup including, but not limited to: chromium, copper, bismuth, cobalt,vanadium, titanium, rhodium, or beryllium. In some implementations ofthe invention, ELR material 360 may be an iron pnictide and modifyingmaterial 1020 may be selected from the group consisting of: chromium,copper, bismuth, cobalt, vanadium, titanium, rhodium, and beryllium. Insome implementations of the invention, ELR material 360 may be an ironpnictide and modifying material 1020 may be another modifying material.

In some implementations of the invention, various combinations of otherELR materials and modifying materials may be used. For example, in someimplementations of the invention, ELR material 360 may be magnesiumdiboride (“MgB₂”). By itself, magnesium diboride has a transitiontemperature of approximately 39K. In some implementations of theinvention, ELR material 360 may be magnesium diboride and modifyingmaterial 1020 may be an oxygen bonding conductive material. In someimplementations of the invention, ELR material 360 may be magnesiumdiboride and modifying material 1020 may be selected from the groupincluding, but not limited to: chromium, copper, bismuth, cobalt,vanadium, titanium, rhodium, or beryllium. In some implementations ofthe invention, ELR material 360 may be magnesium diboride and modifyingmaterial 1020 may be selected from the group consisting of: chromium,copper, bismuth, cobalt, vanadium, titanium, rhodium, and beryllium. Insome implementations of the invention, ELR material 360 may be magnesiumdiboride and modifying material 1020 may be another modifying material.

In some implementations of the invention, modifying material 1020 may belayered onto a sample of ELR material 360 using various techniques forlayering one composition onto another composition as would beappreciated. For example, such layering techniques include, but are notlimited to, pulsed laser deposition, evaporation includingcoevaporation, e-beam evaporation and activated reactive evaporation,sputtering including magnetron sputtering, ion beam sputtering and ionassisted sputtering, cathodic arc deposition, CVD, organometallic CVD,plasma enhanced CVD, molecular beam epitaxy, a sol-gel process, liquidphase epitaxy and/or other layering techniques. In some implementationsof the invention, ELR material 360 may be layered onto a sample ofmodifying material 1020 using various techniques for layering onecomposition onto another composition. In some implementations of theinvention, a single atomic layer of modifying material 1020 (i.e., alayer of modifying material 1020 having a thickness substantially equalto a single atom or molecule of modifying material 1020) may be layeredonto a sample of ELR material 360. In some implementations of theinvention, a single unit layer of the modifying material (i.e., a layerof the modifying material having a thickness substantially equal to asingle unit (e.g., atom, molecule, crystal, or other unit) of themodifying material) may be layered onto a sample of the ELR material. Insome implementations of the invention, the ELR material may be layeredonto a single unit layer of the modifying material. In someimplementations of the invention, two or more unit layers of themodifying material may be layered onto the ELR material. In someimplementations of the invention, the ELR material may be layered ontotwo or more unit layers of the modifying material.

In some implementations of the invention, modifying ELR material 360with modifying material 1020 maintains aperture 310 within modified ELRmaterial 1060 at temperatures at, about, or above that of the boilingpoint of nitrogen. In some implementations of the invention, aperture310 is maintained at temperatures at, about, or above that the boilingpoint of carbon dioxide. In some implementations of the invention,aperture 310 is maintained at temperatures at, about, or above that ofthe boiling point of ammonia. In some implementations of the invention,aperture 310 is maintained at temperatures at, about, or above that ofthe boiling point of various formulations of Freon. In someimplementations of the invention, aperture 310 is maintained attemperatures at, about, or above that of the melting point of water. Insome implementations of the invention, aperture 310 is maintained attemperatures at, about, or above that of the melting point of a solutionof water and antifreeze. In some implementations of the invention,aperture 310 is maintained at temperatures at, about, or above that ofroom temperature (e.g., 21° C.). In some implementations of theinvention, aperture 310 is maintained at temperatures at, about, orabove a temperature selected from one of the following set oftemperatures: 150K, 160K, 170K, 180K, 190K, 200K, 210K, 220K, 230K,240K, 250K, 260K, 270K, 280K, 290K, 300K, 310K. In some implementationsof the invention, aperture 310 is maintained at temperatures within therange of 150K to 315K.

FIGS. 14A-14G illustrate test results 1400 obtained as described above.Test results 1400 include a plot of resistance of modified ELR material1060 as a function of temperature (in K). More particularly, testresults 1400 correspond to modified ELR material 1060 where modifyingmaterial 1020 corresponds to chromium and where ELR material 360corresponds to YBCO. FIG. 14A includes test results 1400 over a fullrange of temperature over which resistance of modified ELR material 1060was measured, namely 84K to 286K. In order to provide further detail,test results 1400 were broken into various temperature ranges andillustrated. In particular, FIG. 14B illustrates those test results 1400within a temperature range from 240K to 280K; FIG. 14C illustrates thosetest results 1400 within a temperature range from 210K to 250K;

FIG. 14D illustrates those test results 1400 within a temperature rangefrom 180K to 220K; FIG. 14E illustrates those test results 1400 within atemperature range from 150K to 190K; FIG. 14F illustrates those testresults 1400 within a temperature range from 120K to 160K; and FIG. 14Gillustrates those test results 1400 within a temperature range from84.5K to 124.5K.

Test results 1400 demonstrate that various portions of modified ELRmaterial 1060 operate in an ELR state at higher temperatures relative toELR material 360. Six sample analysis test runs were made. For eachsample analysis test run, modified ELR material 1060 was slowly cooledfrom approximately 286K to 83K. While being cooled, the current sourceapplied +60 nA and −60 nA of current in a delta mode configuration inorder to reduce impact of any DC offsets and/or thermocouple effects. Atregular time intervals, the voltage across modified ELR material 1060was measured by the voltmeter. For each sample analysis test run, thetime series of voltage measurements were filtered using a 512-point fastFourier transform (“FFT”). All but the lowest 44 frequencies from theFFT were eliminated from the data and the filtered data was returned tothe time domain. The filtered data from each sample analysis test runwere then merged together to produce test results 1400. Moreparticularly, all the resistance measurements from the six sampleanalysis test runs were organized into a series of temperature ranges(e.g., 80K-80.25K, 80.25K to 80.50, 80.5K to 80.75K, etc.) in a mannerreferred to as “binning.” Then the resistance measurements in eachtemperature range were averaged together to provide an averageresistance measurement for each temperature range. These averageresistance measurements form test results 1400.

Test results 1400 include various discrete steps 1410 in the resistanceversus temperature plot, each of such discrete steps 1410 representing arelatively rapid change in resistance over a relatively narrow range oftemperatures. At each of these discrete steps 1410, discrete portions ofmodified ELR material 1060 begin propagating electrical charge up tosuch portions' charge propagating capacity at the respectivetemperatures. At very small scales, the surface of ELR material 360being modified is not perfectly smooth, and thus apertures 310 exposedwithin the surface of ELR material 360 typically do not extend acrossthe entire width or length of the sample of modified ELR material 1060.Accordingly, in some implementations of the invention, modifyingmaterial 1020 covers an entire surface of ELR material 360 and may actas a conductor that carries electrical charge between apertures 310.

Before discussing test results 1400 in further detail, variouscharacteristics of ELR material 360 and modifying material 1020 arediscussed. Resistance versus temperature (“R-T”) profiles of thesematerials individually are generally well known. The individual R-Tprofiles of these materials are not believed to include features similarto discrete steps 1410 found in test results 1400. In fact, unmodifiedsamples of ELR material 360 and samples of modifying material 1020 alonehave been tested under similar and often identical testing andmeasurement configurations. In each instance, the R-T profile of theunmodified samples of ELR material 360 and the R-T profile of themodifying material alone did not include any features similar todiscrete steps 1410. Accordingly, discrete steps 1410 are the result ofmodifying ELR material 360 with modifying material 1020 to maintainaperture 310 at increased temperatures thereby allowing modifiedmaterial 1060 to remain in an ELR state at such increased temperaturesin accordance with various implementations of the invention.

At each of discrete steps 1410, various ones of apertures 310 withinmodified ELR material 1060 start propagating electrical charge up toeach aperture's 310 charge propagating capacity. As measured by thevoltmeter, each charge propagating aperture 310 appears as ashort-circuit, dropping the apparent voltage across the sample ofmodified ELR material 1060 by a small amount. The apparent voltagecontinues to drop as additional ones of apertures 310 start propagatingelectrical charge until the temperature of the sample of modified ELRmaterial 1060 reaches the transition temperature of ELR material 360(i.e., the transition temperature of the unmodified ELR material whichin the case of YBCO is approximately 90K).

Test results 1400 indicate that certain apertures 310 within modifiedELR material 1060 propagate electrical charge at approximately 97K,100K, 103K, 113K, 126K, 140K, 146K, 179K, 183.5K, 200.5K, 237.5K, and250K. Certain apertures 310 within modified ELR material 1060 maypropagate electrical charge at other temperatures within the fulltemperature range as would be appreciated.

Test results 1400 include various other relatively rapid changes inresistance over a relatively narrow range of temperatures not otherwiseidentified as a discrete step 1410. Some of these other changes maycorrespond to artifacts from data processing techniques used on themeasurements obtained during the test runs (e.g., FFTs, filtering,etc.). Some of these other changes may correspond to changes inresistance due to resonant frequencies in modified crystalline structure1010 affecting aperture 310 at various temperatures. Some of these otherchanges may correspond to additional discrete steps 1410. In addition,changes in resistance in the temperature range of 270-274K are likely tobe associated with water present in modified ELR material 1060, some ofwhich may have been introduced during preparation of the sample ofmodified ELR material 1060.

In addition to discrete steps 1410, test results 1400 differ from theR-T profile of ELR material 360 in that modifying material 1020 conductswell at temperatures above the transition temperature of ELR material360 whereas ELR material 360 typically does not.

FIG. 15 illustrates additional test results 1500 for samples of ELRmaterial 360 and modifying material 1020. More particularly, for testresults 1500, modifying material 1020 corresponds to chromium and ELRmaterial 360 corresponds to YBCO. For test results 1500, samples of ELRmaterial 360 were prepared, using various techniques discussed above, toexpose a face of crystalline structure 300 parallel to the a-plane orthe b-plane. Test results 1500 were gathered using a lock-in amplifierand a K6221 current source, which applied a 10nA current at 24.0, Hz tomodified ELR material 1060. Test results 1500 include a plot ofresistance of modified ELR material 1060 as a function of temperature(in K). FIG. 15 includes test results 1500 over a full range oftemperature over which resistance of modified ELR material 1060 wasmeasured, namely 80K to 275K. Test results 1500 demonstrate that variousportions of modified ELR material 1060 operate in an ELR state at highertemperatures relative to ELR material 360. Five sample analysis testruns were made with a sample of modified ELR material 1060. For eachsample analysis test run, the sample of modified ELR material 1060 wasslowly warmed from 80K to 275K. While being warmed, the voltage acrossthe sample of modified ELR material 1060 was measured at regular timeintervals and the resistance was calculated based on the source current.For each sample analysis test run, the time series of resistancemeasurements were filtered using a 1024-point FFT. All but the lowest 15frequencies from the FFT were eliminated from the data and the filteredresistance measurements were returned to the time domain. The filteredresistance measurements from each sample analysis test run were thenmerged together using the binning process referred to above to producetest results 1500. Then the resistance measurements in each temperaturerange were averaged together to provide an average resistancemeasurement for each temperature range. These average resistancemeasurements form test results 1500.

Test results 1500 include various discrete steps 1510 in the resistanceversus temperature plot, each of such discrete steps 1510 representing arelatively rapid change in resistance over a relatively narrow range oftemperatures, similar to discrete steps 1410 discussed above withrespect to FIGS. 14A-14G. At each of these discrete steps 1510, discreteportions of modified ELR material 1060 propagate electrical charge up tosuch portions' charge propagating capacity at the respectivetemperatures.

Test results 1500 indicate that certain apertures 310 within modifiedELR material 1060 propagate electrical charge at approximately 120K,145K, 175K, 225K, and 250K. Certain apertures 310 within modified ELRmaterial 1060 may propagate electrical charge at other temperatureswithin the full temperature range as would be appreciated.

FIGS. 16-20 illustrate additional test results for samples of ELRmaterial 360 and various modifying materials 1020. For these additionaltest results, samples of ELR material 360 were prepared, using varioustechniques discussed above, to expose a face of crystalline structure300 substantially parallel to the a-plane or the b-plane or somecombination of the a-plane or the b-plane and the modifying material waslayered onto these exposed faces. Each of these modified samples wasslowly cooled from approximately 300K to 80K. While being warmed, acurrent source applied a current in a delta mode configuration throughthe modified sample as described below. At regular time intervals, thevoltage across the modified sample was measured. For each sampleanalysis test run, the time series of voltage measurements were filteredin the frequency domain using an FFT by removing all but the lowestfrequencies, and the filtered measurements were returned to the timedomain. The number of frequencies kept is in general different for eachdata set. The filtered data from each of test runs were then binned andaveraged together to produce the test results illustrated in FIGS.16-21.

FIG. 16 illustrates test results 1600 including a plot of resistance ofmodified ELR material 1060 as a function of temperature (in K). For testresults 1600, modifying material 1020 corresponds to vanadium and ELRmaterial 360 corresponds to YBCO. Test results 1600 were produced over11 test runs using a 20nA current source, a 1024-point FFT wasperformed, and information from all but the lowest 12 frequencies wereeliminated. Test results 1600 demonstrate that various portions ofmodified ELR material 1060 operate in an ELR state at highertemperatures relative to ELR material 360. Test results 1600 includevarious discrete steps 1610 in the resistance versus temperature plot,similar to those discussed above with regard to FIGS. 14A-14G. Testresults 1600 indicate that certain apertures 310 within modified ELRmaterial 1060 propagate electrical charge at approximately 267K, 257K,243K, 232K, and 219K. Certain apertures 310 within modified ELR material1060 may propagate electrical charge at other temperatures.

FIG. 17 illustrates test results 1700 including a plot of resistance ofmodified ELR material 1060 as a function of temperature (in K). For testresults 1700, modifying material 1020 corresponds to bismuth and ELRmaterial 360 corresponds to YBCO. Test results 1700 were produced over 5test runs using a 400nA current source, a 1024-point FFT was performed,and information from all but the lowest 12 frequencies were eliminated.Test results 1700 demonstrate that various portions of modified ELRmaterial 1060 operate in an ELR state at higher temperatures relative toELR material 360. Test results 1700 include various discrete steps 1710in the resistance versus temperature plot, similar to those discussedabove with regard to FIGS. 14A-14G. Test results 1700 indicate thatcertain apertures 310 within modified ELR material 1060 propagateelectrical charge at approximately 262K, 235K, 200K, 172K, and 141K.Certain apertures 310 within modified ELR material 1060 may propagateelectrical charge at other temperatures.

FIG. 18 illustrates test results 1800 including a plot of resistance ofmodified ELR material 1060 as a function of temperature (in K). For testresults 1800, modifying material 1020 corresponds to copper and ELRmaterial 360 corresponds to YBCO. Test results 1800 were produced over 6test runs using a 200nA current source, a 1024-point FFT was performed,and information from all but the lowest 12 frequencies were eliminated.Test results 1800 demonstrate that various portions of modified ELRmaterial 1060 operate in an ELR state at higher temperatures relative toELR material 360. Test results 1800 include various discrete steps 1810in the resistance versus temperature plot, similar to those discussedabove with regard to FIGS. 14A-14G. Test results 1800 indicate thatcertain apertures 310 within modified ELR material 1060 propagateelectrical charge at approximately 268K, 256K, 247K, 235K, and 223K.Certain apertures 310 within modified ELR material 1060 may propagateelectrical charge at other temperatures.

FIG. 19 illustrates test results 1900 including a plot of resistance ofmodified ELR material 1060 as a function of temperature (in K). For testresults 1900, modifying material 1020 corresponds to cobalt and ELRmaterial 360 corresponds to YBCO. Test results 1900 were produced over11 test runs using a 400nA current source, a 1024-point FFT wasperformed, and information from all but the lowest 12 frequencies wereeliminated. Test results 1900 demonstrate that various portions ofmodified ELR material 1060 operate in an ELR state at highertemperatures relative to ELR material 360. Test results 1900 includevarious discrete steps 1910 in the resistance versus temperature plot,similar to those discussed above with regard to FIGS. 14A-14G. Testresults 1900 indicate that certain apertures 310 within modified ELRmaterial 1060 propagate electrical charge at approximately 265K, 236K,205K, 174K, and 143K. Certain apertures 310 within modified ELR material1060 may propagate electrical charge at other temperatures.

FIG. 20 illustrates test results 2000 including a plot of resistance ofmodified ELR material 1060 as a function of temperature (in K). For testresults 2000, modifying material 1020 corresponds to titanium and ELRmaterial 360 corresponds to YBCO. Test results 2000 were produced over25 test runs using a 100nA current source, a 512-point FFT wasperformed, and information from all but the lowest 11 frequencies wereeliminated. Test results 2000 demonstrate that various portions ofmodified ELR material 1060 operate in an ELR state at highertemperatures relative to ELR material 360. Test results 2000 includevarious discrete steps 2010 in the resistance versus temperature plot,similar to those discussed above with regard to FIGS. 14A-14G. Testresults 2000 indicate that certain apertures 310 within modified ELRmaterial 1060 propagate electrical charge at approximately 266K, 242K,and 217K. Certain apertures 310 within modified ELR material 1060 maypropagate electrical charge at other temperatures.

FIG. 21A-21B illustrates test results 2100 including a plot ofresistance of modified ELR material 1060 as a function of temperature(in K). For test results 2100, modifying material 1020 corresponds tochromium and ELR material 360 corresponds to BSSCO. FIG. 21A includestest results 2100 over a full range of temperature over which resistanceof modified ELR material 1060 was measured, namely 80K to 270K. In orderto provide further detail, test results 2100 were expanded over atemperature range of 150K-250K as illustrated in FIG. 21B. Test results2100 were gathered in a manner similar to those discussed above withregard to FIG. 16-20. In particular, test results 2100 were producedover 25 test runs using a 300nA current source. The data from these testruns was Savitzy-Golay smoothed, using 64 side points and 4^(th) orderpolynomials. Test results 2100 demonstrate that various portions ofmodified ELR material 1060 operate in an ELR state at highertemperatures relative to ELR material 360 (here, BSSCO). Test results2100 include various discrete steps 2110 in the resistance versustemperature plot, similar to those discussed above with regard to FIGS.14A-14G. Test results 2100 indicate that certain apertures withinmodified ELR material 1060 propagate electrical charge at approximately184K and 214K. Certain apertures 310 within modified ELR material 1060may propagate electrical charge at other temperatures.

In other experiments, modifying material 1020 was layered onto a surfaceof ELR material 360 substantially parallel to the c-plane of crystallinestructure 300. These tests results (not otherwise illustrated)demonstrate that layering a surface of ELR material 360 parallel to thec-plane with modifying material 1020 did not produce any discrete stepssuch as those described above (e.g., discrete steps 1410). These testresults indicate that modifying a surface of ELR material 360 that isperpendicular to a direction in which ELR material 360 does not (ortends to not) exhibit the resistance phenomenon does not improve theoperating characteristics of the unmodified ELR material. In otherwords, modifying such surfaces of ELR material 360 may not maintainaperture 310. In accordance with various principles of the invention,modifying material should be layered with surfaces of the ELR materialthat are parallel to the direction in which ELR material does not (ortends to not) exhibit the resistance phenomenon. More particularly, andfor example, with regard to ELR material 360 (illustrated in FIG. 3),modifying material 1020 should be bonded to an “a-c” face or a “b-c”face of crystalline structure 300 (both of which faces are parallel tothe c-axis) in ELR material 360 (which tends not to exhibit theresistance phenomenon in the direction of the c-axis) in order tomaintain aperture 310.

FIG. 22 illustrates an arrangement 2200 including alternating layers ofELR material 360 and a modifying material 1020 useful for propagatingadditional electrical charge according to various implementations of theinvention. Such layers may be deposited onto one another using variousdeposition techniques. Various techniques may be used to improvealignment of crystalline structures 300 within layers of ELR material360. Improved alignment of crystalline structures 300 may result inapertures 310 of increased length through crystalline structure 300which in turn may provide for operation at higher temperatures and/orwith increased charge propagating capacity. Arrangement 2200 providesincreased numbers of apertures 310 within modified ELR material 1060 ateach interface between adjacent layers of modifying material 1020 andELR material 360. Increased numbers of apertures 310 may increase acharge propagating capacity of arrangement 2200.

In some implementations of the invention, any number of layers may beused. In some implementations of the invention, other ELR materialsand/or other modifying materials may be used. In some implementations ofthe invention, additional layers of other material (e.g., insulators,conductors, or other materials) may be used between paired layers of ELRmaterial 360 and modifying material 1020 to mitigate various effects(e.g., magnetic effects, migration of materials, or other effects) or toenhance the characteristics of the modified ELR material 1060 formedwithin such paired layers. In some implementations of the invention, notall layers are paired. In other words, arrangement 2200 may have one ormore extra (i.e., unpaired) layers of ELR material 360 or one or moreextra layers of modifying material 1020.

FIG. 23 illustrates additional layers 2310 (illustrated as a layer2310A, a layer 2310B, a layer 2310C, and a layer 2310D) of modifiedcrystalline structure 1010 in modified ELR material 1060 according tovarious implementations of the invention. As illustrated, modified ELRmaterial 1060 includes various apertures 310 (illustrated as an aperture310A, an aperture 310B, and an aperture 310C) at different distancesinto material 1060 from modifying material 1020 that form bonds withatoms of crystalline structure 300 (of FIG. 3). Aperture 310A is nearestmodifying material 1020, followed by aperture 310B, which in turn isfollowed by aperture 310C, etc. In accordance with variousimplementations of the invention, an impact of modifying material 1020is greatest with respect to aperture 310A, followed by a lesser impactwith respect to aperture 310B, which in turn is followed by a lesserimpact with respect to aperture 310C, etc. According to someimplementations of the invention, modifying material 1020 should bettermaintain aperture 310A than either aperture 310B or aperture 310C due toaperture 310A's proximity to modifying material 1020; likewise,modifying material 1020 should better maintain aperture 310B thanaperture 310C due to aperture 310B's proximity to modifying material1020, etc. According to some implementations of the invention, modifyingmaterial 1020 should better maintain the cross-section of aperture 310Athan the cross-sections of either aperture 310B or aperture 310C due toaperture 310A's proximity to modifying material 1020; likewise,modifying material 1020 should better maintain the cross-section ofaperture 310B than the cross-section of aperture 310C due to aperture310B's proximity to modifying material 1020, etc. According to someimplementations of the invention, modifying material 1020 should have agreater impact on a charge propagating capacity of aperture 310A at aparticular temperature than on a charge propagating capacity of eitheraperture 310B or aperture 310C at that particular temperature due toaperture 310A's proximity to modifying material 1020; likewise,modifying material 1020 should have a greater impact on the chargepropagating capacity of aperture 310B at a particular temperature thanon the charge propagating capacity of aperture 310C at that particulartemperature due to aperture 310B's proximity to modifying material 1020,etc. According to some implementations of the invention, modifyingmaterial 1020 should enhance the propagation of electrical chargethrough aperture 310A more than the propagation of electrical chargethrough either aperture 310B or aperture 310C due to aperture 310A'sproximity to modifying material 1020; likewise, modifying material 1020should enhance the propagation of electrical charge through aperture310B more than the propagation of electrical charge through aperture310C due to aperture 310B's proximity to modifying material 1020, etc.

Various test results described above, for example, test results 1400 ofFIG. 14, among others, support these aspects of various implementationsof the invention, i.e., generally, that the impact of modifying material1020 on apertures 310 varies in relation to their proximity to oneanother. In particular, each discrete step 1410 in test results 1400 maycorrespond to a change in electrical charge carried by modified ELRmaterial 1060 as those apertures 310 in a particular layer 2310 (or moreappropriately, those apertures 310 formed between adjacent layers 2310as illustrated) propagate electrical charge up to such apertures' 310charge propagating capacity. Those apertures 310 in layers 2310 closerin proximity to modifying material 1020 correspond to discrete steps1410 at higher temperatures whereas those apertures 310 in layers 2310further from modifying material 1020 correspond to discrete steps 1410at lower temperatures. Discrete steps 1410 are “discrete” in the sensethat apertures 310 at a given relative distance to modifying material1020 (i.e., apertures 310A between layers 2310A and 2310B) propagateelectrical charge at a particular temperature and quickly reach theirmaximum charge propagating capacity. Another discrete step 1410 isreached when apertures 310 at an increased distance from modifyingmaterial 1020 (i.e., apertures 310B between layers 2310B and 2310C)propagate electrical charge at a lower temperature as a result of theincreased distance and hence the lessened impact of modifying material1020 on those apertures 310. Each discrete step 1410 corresponds toanother set of apertures 310 beginning to carry electrical charge basedon their distance from modifying material 1020. At some distance,however, modifying material 1020 may have insufficient impact on someapertures 310 to cause them to carry electrical charge at a highertemperature than they otherwise would; hence, such apertures 310propagate electrical charge at a temperature consistent with that of ELRmaterial 360.

In some implementations of the invention, a distance between modifyingmaterial 1020 and apertures 310 is reduced so as to increase impact ofmodifying material 1020 on more apertures 310. In effect, more apertures310 should propagate electrical charge at discrete steps 1410 associatedwith higher temperatures. For example, in arrangement 2200 of FIG. 22and in accordance with various implementations of the invention, layersof ELR material 360 may be made to be only a few unit cells thick inorder to reduce the distance between apertures 310 in ELR material 360and modifying material 1020. Reducing this distance should increase thenumber of apertures 310 impacted by modifying material 1020 at a giventemperature. Reducing this distance also increases the number ofalternating layers of ELR material 360 in a given overall thickness ofarrangement 2200 thereby increasing an overall charge propagatingcapacity of arrangement 2200.

FIG. 24 illustrates a film 2400 of an ELR material 2410 formed on asubstrate 2420, although, substrate 2420 may not be necessary in variousimplementations of the invention. In various implementations of theinvention, film 2400 may be formed into a tape having a length, forexample, greater than 10 cm, 1 m, 1 km or more. Such tapes may beuseful, for example, as ELR conductors or ELR wires. As would beappreciated, while various implementations of the invention aredescribed in reference to ELR films, such implementations apply to ELRtapes as well.

For purposes of this description and as illustrated in FIG. 24, film2400 has a primary surface 2430 and a principal axis 2440. Principalaxis 2440 corresponds to a axis extending along a length of film 2400(as opposed to a width of film 2400 or a thickness of film 2400).Principal axis 2440 corresponds to a primary direction in whichelectrical charge flows through film 2400. Primary surface 2430corresponds to the predominant surface of film 2400 as illustrated inFIG. 24, and corresponds to the surface bound by the width and thelength of film 2400. It should be appreciated that films 2400 may havevarious lengths, widths, and/or thicknesses without departing from thescope of the invention.

In some implementations of the invention, during the fabrication of film2400, the crystalline structures of ELR material 2410 may be orientedsuch that their c-axis is substantially perpendicular to primary surface2430 of film 2400 and either the a-axis or the b-axis of theirrespective crystalline structures is substantially parallel to principalaxis 2440. Hence, as illustrated in FIG. 24, the c-axis is referenced byname and the a-axis and the b-axis are not specifically labeled,reflecting their interchangeability for purposes of describing variousimplementations of the invention. In some fabrication processes of film2400, the crystalline structures of ELR material may be oriented suchthat any given line within the c-plane may be substantially parallelwith principal axis 2440.

For purposes of this description, films 2400 having the c-axis of theirrespective crystalline structures oriented substantially perpendicularto primary surface 2430 (including film 2400 depicted in FIG. 24) arereferred to as “c-films” (i.e., c-film 2400). C-film 2400, with ELRmaterial 2410 comprised of YBCO, is commercially available from, forexample, American Superconductors™ (e.g., 344 Superconductor—Type 348C)or Theva Dünnschichttechnik GmbH (e.g., HTS coated conductors).

In some implementations of the invention, substrate 2420 may include asubstrate material including, but not limited to, MgO, STO, LSGO, apolycrystalline material such as a metal or a ceramic, an inert oxidematerial, a cubic oxide material, a rare earth oxide material, or othersubstrate material as would be appreciated.

According to various implementations of the invention (and as describedin further detail below), a modifying material 1020 is layered onto anappropriate surface of ELR material 2410, where the appropriate surfaceof ELR material 2410 corresponds to any surface not substantiallyperpendicular to the c-axis of the crystalline structure of ELR material2410. In other words, the appropriate surface of ELR material 2410 maycorrespond to any surface that is not substantially parallel to theprimary surface 2430. In some implementations of the invention, theappropriate surface of ELR material 2410 may correspond to any surfacethat is substantially parallel to the c-axis of the crystallinestructure of ELR material 2410. In some implementations of theinvention, the appropriate surface of ELR material 2410 may correspondto any surface that is not substantially perpendicular to the c-axis ofthe crystalline structure of ELR material 2410. In order to modify anappropriate surface of c-film 2400 (whose primary surface 2430 issubstantially perpendicular to the c-axis of the crystalline structureof ELR material 2410), the appropriate surface of ELR material 2410 maybe formed on or within c-film 2400. In some implementations of theinvention, primary surface 2430 may be processed to expose appropriatesurface(s) of ELR material 2410 on or within c-film 2400 on which tolayer modifying material. In some implementations of the invention,primary surface 2430 may be processed to expose one or more apertures210 of ELR material 2410 on or within c-film 2400 on which to layermodifying material. It should be appreciated, that in variousimplementations of the invention, modifying material may be layered ontoprimary surface 2430 in addition to the appropriate surfaces referencedabove.

Processing of primary surface 2430 of c-film 2400 to expose appropriatesurfaces and/or apertures 210 of ELR material 2410 may comprise variouspatterning techniques, including various wet processes or dry processes.Various wet processes may include lift-off, chemical etching, or otherprocesses, any of which may involve the use of chemicals and which mayexpose various other surfaces within c-film 2400. Various dry processesmay include ion or electron bream irradiation, laser direct-writing,laser ablation or laser reactive patterning or other processes which mayexpose various appropriate surfaces and/or apertures 210 of ELR material2410 within c-film 2400.

As illustrated in FIG. 25, primary surface 2430 of c-film 2400 may beprocessed to expose an appropriate surface within c-film 2400. Forexample, c-film 2400 may be processed to expose a face within c-film2400 substantially parallel to the b-plane of crystalline structure 100or a face within c-film 2400 substantially parallel to the a-plane ofcrystalline structure 100. More generally, in some implementations ofthe invention, primary surface 2430 of c-film 2400 may be processed toexpose an appropriate surface within c-film 2400 corresponding to ana/b-c face (i.e., a face substantially parallel to ab-plane). In someimplementations of the invention, primary surface 2430 of c-film may beprocessed to expose any face within c-film 2400 that is notsubstantially parallel with primary surface 2430. In someimplementations of the invention, primary surface 2430 of c-film may beprocessed to expose any face within c-film 2400 that is notsubstantially parallel with primary surface 2430 and also substantiallyparallel with principal axis 2440. Any of these faces, includingcombinations of these faces, may correspond to appropriate surfaces ofELR material 2410 on or within c-film 2400. According to variousimplementations of the invention, appropriate surfaces of ELR material2410 provide access to or otherwise “expose” apertures 210 in ELRmaterial 2410 for purposes of maintaining such apertures 210.

In some implementations of the invention, as illustrated in FIG. 25,primary surface 2430 is processed to form one or more grooves 2510 inprimary surface 2430. Grooves 2510 include one or more appropriatesurfaces (i.e., surfaces other than one substantially parallel toprimary surface 2430) on which to deposit modifying material. Whilegrooves 2510 are illustrated in FIG. 25 as having a cross sectionsubstantially rectangular in shape, other shapes of cross sections maybe used as would be appreciated. In some implementations of theinvention, the width of grooves 2510 may be greater than 10 nm. In someimplementations of the invention and as illustrated in FIG. 25, thedepth of grooves 2510 may be less than a full thickness of ELR material2410 of c-film 2400. In some implementations of the invention and asillustrated in FIG. 26, the depth of grooves 2510 may be substantiallyequal to the thickness of ELR material 2410 of c-film 2400. In someimplementations of the invention, the depth of grooves 2510 may extendthrough ELR material 2410 of c-film 2400 and into substrate 2420 (nototherwise illustrated). In some implementations of the invention, thedepth of grooves 2510 may correspond to a thickness of one or more unitsof ELR material 2410 (not otherwise illustrated). Grooves 2510 may beformed in primary surface 2430 using various techniques, such as, butnot limited to, laser etching, or other techniques.

In some implementations of the invention, the length of grooves 2510 maycorrespond to the full length of c-film 2400. In some implementations ofthe inventions, grooves 2510 are substantially parallel to one anotherand to principal axis 2440. In some implementations of the invention,grooves 2510 may take on various configurations and/or arrangements inaccordance with the various aspects of the invention. For example,grooves 2510 may extend in any manner and/or direction and may includelines, curves and/or other geometric shapes in cross-section withvarying sizes and/or shapes along its extent.

While various aspects of the invention are described as forming grooves2510 within primary surface 2430, it will be appreciated that bumps,angles, or protrusions that include appropriate surfaces of ELR material2410 may be formed on substrate 2420 to accomplish similar geometries.

According to various implementations of the invention, c-film 2400 maybe modified to form various modified c-films. For example, referring toFIG. 27, a modifying material 2720 (i.e., modifying material 1020,modifying material 1020) may be layered onto primary surface 2430 andinto grooves 2510 formed within primary surface 2430 of an unmodifiedc-film (e.g., c-film 2400) and therefore onto various appropriatesurfaces 2710 to form a modified c-film 2700. Appropriate surfaces 2710may include any appropriate surfaces discussed above. While appropriatesurfaces 2710 are illustrated in FIG. 27 as being perpendicular toprimary surface 2430, this is not necessary as would be appreciated fromthis description.

In some implementations of the invention, modifying material 2720 may belayered onto primary surface 2430 and into grooves 2510 as illustratedin FIG. 27. In some implementations, such as illustrated in FIG. 28,modifying material 2720 may be removed from primary surface 2430 to formmodified c-film 2800 using various techniques such that modifyingmaterial 2720 remains only in grooves 2510 (e.g., various polishingtechniques). In some implementations, modified c-film 2800 may beaccomplished by layering modifying material 2720 only in grooves 2510.In other words, in some implementations, modifying material 2720 may belayered only into grooves 2510 and/or onto appropriate surfaces 2710,without layering modifying material 2720 onto primary surface 2430 ormay be layered such that modifying material 2720 does not bond orotherwise adhere to primary surface 2430 (e.g., using various maskingtechniques). In some implementations of the invention, various selectivedeposition techniques may be employed to layer modifying material 2720directly onto appropriate surfaces 2710.

The thickness of modifying material 2720 in grooves 2510 and/or onprimary surface 2430 may vary according to various implementations ofthe invention. In some implementations of the invention, a single unitlayer of modifying material 2720 (i.e., a layer having a thicknesssubstantially equal to a single unit of modifying material 2720) may belayered onto appropriate surfaces 2710 of grooves 2510 and/or on primarysurface 2430. In some implementations of the invention, two or more unitlayers of modifying material 2720 may be layered into onto appropriatesurfaces 2710 of grooves 2510 and/or on primary surface 2430.

Modified c-films 2700, 2800 (i.e., c-film 2400 modified with modifyingmaterial 2720) in accordance with various implementations of theinvention may be useful for achieving one or more improved operationalcharacteristics over those of unmodified c-film 2400.

As illustrated in FIG. 29, in some implementations of the invention,primary surface 2430 of unmodified c-film 2400 may be modified, via achemical etch, to expose or otherwise increase an area of appropriatesurfaces 2710 available on primary surface 2430. In some implementationsof the invention, one manner of characterizing an increased area ofappropriate surfaces 2710 within primary surface 2430 may be based onthe root mean square (RMS) surface roughness of primary surface 2430 ofc-film 2400. In some implementations of the invention, as a result ofchemical etching, primary surface 2430 of c-film 2400 may include anetched surface 2910 having a surface roughness in a range of about 1 nmto about 50 nm. RMS surface roughness may be determined using, forexample, Atomic Force Microscopy (AFM), Scanning Tunneling Microscopy(STM), or SEM and may be based on a statistical mean of an R-range,wherein the R-range may be a range of the radius (r) of a grain size aswould be appreciated. After the chemical etch, an etched surface 2910 ofc-film 2900 may correspond to appropriate surface 2710 of ELR material2410.

As illustrated in FIG. 30, after the chemical etch, modifying material2720 may be layered on to etched surface 2910 of c-film 2900 to form amodified c-film 3000. Modifying material 2720 may cover substantiallyall of surface 2910 and the thickness of modifying material 2720 mayvary in accordance with various implementations of the invention. Insome implementations of the invention, a single unit layer of modifyingmaterial 2720 may be layered onto etched surface 2910. In someimplementations of the invention, two or more unit layers of modifyingmaterial 2720 may be layered onto etched surface 2910.

In some implementations of the invention, films having orientations ofcrystalline structure of ELR material other than that of c-film 2400 maybe used. For example, in reference to FIG. 31, and according to variousimplementations of the invention, instead of the c-axis orientedperpendicular to primary surface 2430 as with c-film 2400, a film 3100may have the c-axis oriented perpendicular to the principal axis 2440and a b-axis of ELR material 3110 oriented perpendicular to primarysurface 2430. Similarly, a film 3100 may have the c-axis orientedperpendicular to the principal axis 2440 and an a-axis of ELR material3110 oriented perpendicular to primary surface 2430. In someimplementations of the invention, film 3100 may have the c-axis orientedperpendicular to the principal axis 2440 and any line parallel to thec-plane oriented along principal axis 2440. As illustrated in FIG. 31,in these implementations of the invention, film 3100 includes ELRmaterial 3110 with the c-axis of its crystalline structure orientedperpendicular to principal axis 2440 and parallel to a primary surface3130 and are generally referred to herein as a-b films 3100. While FIG.31 illustrates the other two axes of the crystalline structure in aparticular orientation, such orientation is not necessary as would beappreciated. As illustrated, a-b films 3100 may include an optionalsubstrate 2420 (as with c-films 2400).

In some implementations of the invention, a-b film 3100 is an a-film,having the c-axis of the crystalline structure of ELR material 3110oriented as illustrated in FIG. 31 and the a-axis perpendicular toprimary surface 3130. Such a-films may be formed via various techniquesincluding those described at Selvamanickam, V., et al., “High CurrentY—Ba—Cu—O Coated Conductor using Metal Organic Chemical Vapor Depositionand Ion Beam Assisted Deposition,” Proceedings of the 2000 AppliedSuperconductivity Conference, Virginia Beach, Va., Sep. 17-22, 2000,which is incorporated herein by reference in its entirety. In someimplementations, a-films may be grown on substrates 2420 formed of thefollowing materials: LGSO, LaSrAlO₄, NdCaAlO₄, Nd₂CuO₄, or CaNdAlO₄.Other substrate materials may be used as would be appreciated.

In some implementations of the invention, a-b film 3100 is a b-film,having the c-axis of the crystalline structure of ELR material 3110oriented as illustrated in FIG. 31 and the b-axis perpendicular toprimary surface 3130.

According to various implementations of the invention, primary surface3130 of a-b film 3100 corresponds to an appropriate surface 2710. Insome implementations that employ a-b film 3100, forming an appropriatesurface of ELR material 3110 may include forming a-b film 3100.Accordingly, for implementations of the invention that include a-b film3100, modifying material 2720 may be layered onto primary surface 3130of a-b film 3100 to create a modified a-b film 3200 as illustrated inFIG. 32. In some implementations of the invention, modifying material2720 may cover primary surface 3130 of a-b film 3100 in whole or inpart. In some implementations of the invention, the thickness ofmodifying material 2720 may vary as discussed above. More particularly,in some implementations of the invention, a single unit layer ofmodifying material 2720 may be layered onto primary surface 3130 of a-bfilm 3100; and in some implementations of the invention, two or moreunit layers of modifying material 2720 may be layered onto primarysurface 3130 of a-b film 3100. In some implementations of the invention,a-b film 3100 may be grooved or otherwise modified as discussed abovewith regard to c-film 2400, for example, to increase an overall area ofappropriate surfaces 2710 of ELR material 3110 on which to layermodifying material 2720.

As would be appreciated, rather than utilizing a-b film 3100, someimplementations of the invention may utilize a layer of ELR material2410 having its crystalline structure oriented in a manner similar tothat of a-b film 3100.

In some implementations of the invention (not otherwise illustrated) abuffer or insulating material may be subsequently layered onto modifyingmaterial 2720 of any of the aforementioned films. In theseimplementations, the buffer or insulating material and the substrateform a “sandwich” with ELR material 2410, 3110 and modifying material2720 there between. The buffer or insulating material may be layeredonto modifying material 2720 as would be appreciated.

Any of the aforementioned materials may be layered onto any othermaterial. For example, ELR materials may be layered onto modifyingmaterials. Likewise, modifying materials may be layered onto ELRmaterials. Further, layering may include combining, forming, ordepositing one material onto the other material as would be appreciated.Layering may use any generally known layering technique, including, butnot limited to, pulsed laser deposition, evaporation includingcoevaporation, e-beam evaporation and activated reactive evaporation,sputtering including magnetron sputtering, ion beam sputtering and ionassisted sputtering, cathodic arc deposition, CVD, organometallic CVD,plasma enhanced CVD, molecular beam epitaxy, a sol-gel process, liquidphase epitaxy and/or other layering technique.

Multiple layers of ELR material 2410, 3110, modifying material 2720,buffer or insulating layers, and/or substrates 1120 may be arranged invarious implementations of the invention. FIG. 33 illustrates variousexemplary arrangements of these layers in accordance with variousimplementations of the invention. In some implementations, a given layermay comprise a modifying material 2720 that also acts as a buffer orinsulating layer or a substrate. Other arrangements or combinations ofarrangements may be used as would be appreciated from reading thisdescription. Furthermore, in some implementations of the invention,various layers of ELR material may have different orientations from oneanother in a given arrangement. For example, one layer of ELR materialin an arrangement may have the a-axis of its crystalline structureoriented along the principal axis 2440 and another layer of the ELRmaterial in the arrangement may have the b-axis of its crystallinestructure oriented along the principal axis 2440. Other orientations maybe used within a given arrangement in accordance with variousimplementations of the invention.

FIG. 34 illustrates a process for creating a modified ELR materialaccording to various implementations of the invention. In an operation3410, an appropriate surface 2710 is formed on or within an ELRmaterial. In some implementations of the invention where ELR materialexists as ELR material 2410 of c-film 2400, appropriate surface 2710 isformed by exposing appropriate surface(s) 2710 on or within primarysurface 2430 of a c-film 2400. In some implementations of the invention,appropriate surfaces of ELR material 2410 may be exposed by modifyingprimary surface 2430 using any of the wet or dry processing techniques,or combinations thereof, discussed above. In some implementations of theinvention, primary surface 2430 may be modified by chemical etching asdiscussed above.

In some implementations of the invention where ELR material exists asELR material 3110 of a-b film 3100 (with or without substrate 2420),appropriate surface 2710 is formed by layering ELR material 3110 (in aproper orientation as described above) onto a surface, which may or maynot include substrate 2420.

In some implementations of the invention, appropriate surfaces 2710include surfaces of ELR material parallel to the ab-plane. In someimplementations of the invention, appropriate surfaces 2710 includefaces of ELR material parallel to the b-plane. In some implementationsof the invention, appropriate surfaces 2710 include faces of ELRmaterial parallel to the a-plane. In some implementations of theinvention, appropriate surfaces 2710 include one or more faces of ELRmaterial parallel to different ab-planes. In some implementations of theinvention, appropriate surfaces 2710 include one or more faces notsubstantially perpendicular to the c-axis of ELR material.

In some implementations of the invention, various optional operationsmay be performed. For example, in some implementations of the invention,appropriate surfaces 2710 or ELR material may be annealed. In someimplementations of the invention, this annealing may be a furnace annealor a rapid thermal processing (RTP) anneal process. In someimplementations of the invention, such annealing may be performed in oneor more annealing operations within predetermined time periods,temperature ranges, and other parameters. Further, as would beappreciated, annealing may be performed in the chemical vapor deposition(CVD) chamber and may include subjecting appropriate surfaces 2710 toany combination of temperature and pressure for a predetermined timewhich may enhance appropriate surfaces 2710. Such annealing may beperformed in a gas atmosphere and with or without plasma enhancement.

In an operation 3420, modifying material 2720 may be layered onto one ormore appropriate surfaces 2710. In some implementations of theinvention, modifying material 2720 may be layered onto appropriatesurfaces 2710 using various layering techniques, including various onesdescribed above.

FIG. 35 illustrates an example of additional processing that may beperformed during operation 3420 according to various implementations ofthe invention. In an operation 3510, appropriate surfaces 2710 may bepolished. In some implementations of the invention, one or more polishesmay be used as discussed above.

In an operation 3520, various surfaces other than appropriate surfaces2710 may be masked using any generally known masking techniques. In someimplementations, all surfaces other than appropriate surfaces 2710 maybe masked. In some implementations of the invention, one or moresurfaces other than appropriate surfaces 2710 may be masked.

In an operation 3530, modifying material 2720 may be layered on to (orin some implementations and as illustrated in FIG. 35, deposited on to)appropriate surfaces 2710 using any generally known layering techniquesdiscussed above. In some implementations of the invention, modifyingmaterial 2720 may be deposited on to appropriate surfaces 2710 usingMBE. In some implementations of the invention, modifying material 2720may be deposited on to appropriate surfaces 2710 using PLD. In someimplementations of the invention, modifying material 2720 may bedeposited on to appropriate surfaces 2710 using CVD. In someimplementations of the invention, approximately 40 nm of modifyingmaterial 2720 may be deposited on to appropriate surfaces 2710, althoughas little as 1.7 nm of certain modifying materials 2720 (e.g., cobalt)has been tested. In various implementations of the invention, muchsmaller amounts of modifying materials 2450, for example, on the orderof a few angstroms, may be used. In some implementation of theinvention, modifying material 2720 may be deposited on to appropriatesurfaces 2710 in a chamber under a vacuum, which may have a pressure of5×10⁻⁶ torr or less. Various chambers may be used including those usedto process semiconductor wafers. In some implementations of theinvention, the CVD processes described herein may be carried out in aCVD reactor, such as a reaction chamber available under the tradedesignation of 7000 from Genus, Inc. (Sunnyvale, Calif.), a reactionchamber available under the trade designation of 5000 from AppliedMaterials, Inc. (Santa Clara, Calif.), or a reaction chamber availableunder the trade designation of Prism from Novelus, Inc. (San Jose,Calif.). However, any reaction chamber suitable for performing MBE, PLDor CVD may be used.

FIG. 36 illustrates a process for forming a modified ELR materialaccording to various implementations of the invention. In particular,FIG. 36 illustrates a process for forming and/or modifying an a-b film3100. In an optional operation 3610, a buffer layer is deposited onto asubstrate 2420. In some implementations of the invention, the bufferlayer includes PBCO or other suitable buffer material. In someimplementations of the invention, substrate 2420 includes LSGO or othersuitable substrate material. In an operation 3620, ELR material 3110 islayered onto substrate 2420 with a proper orientation as described abovewith respect to FIG. 31. As would be appreciated, depending on optionaloperation 3610, ELR material 3110 is layered onto substrate 2420 or thebuffer layer. In some implementations of the invention, the layer of ELRmaterial 3110 is two or more unit layers thick. In some implementationsof the invention, the layer of ELR material 3110 is a few unit layersthick. In some implementations of the invention, the layer of ELRmaterial 3110 is several unit layers thick. In some implementations ofthe invention, the layer of ELR material 3110 is many unit layers thick.In some implementations of the invention, ELR material 3110 is layeredonto substrate 2420 using an IBAD process. In some implementations ofthe invention, ELR material 3110 is layered onto substrate 2420 whilesubject to a magnetic field to improve an alignment of the crystallinestructures within ELR material 3110.

In an optional operation 3630, appropriate surface(s) 2710 (which withrespect to a-b films 3100, corresponds to primary surface 3130) of ELRmaterial 3110 is polished using various techniques described above. Insome implementations of the invention, the polishing is accomplishedwithout introducing impurities onto appropriate surfaces 2710 of ELRmaterial 3110. In some implementations of the invention, the polishingis accomplished without breaking the clean chamber. In an operation3640, modifying material 2720 is layered onto appropriate surfaces 2710.In an optional operation 3650, a covering material, such as, but notlimited to, silver, is layered over entire modifying material 2720.

The flowcharts, illustrations, and block diagrams of the figuresillustrate the architecture, functionality, and operation of possibleimplementations of methods and products according to variousimplementations of the invention. It should also be noted that, in somealternative implementations, the functions noted in the blocks may occurout of the order noted in the figures. For example, two blocks shown insuccession may, in fact, be executed substantially concurrently, or theblocks may sometimes be executed in the reverse order, depending uponthe functionality involved.

Furthermore, although the foregoing description is directed towardvarious implementations of the invention, it is noted that othervariations and modifications will be apparent to those skilled in theart, and may be made without departing from the spirit or scope of theinvention. Moreover, various features described in connection with oneimplementation of the invention may be used in conjunction orcombination with various other features or other implementationsdescribed herein, even if not expressly stated above.

1. A composition comprising: a first layer comprising BSSCO; and asecond layer comprising a modifying material, wherein the modifyingmaterial of the second layer is bonded to the BSSCO of the first layer,wherein the modifying material comprises an element selected from thegroup consisting of: chromium, copper, bismuth, cobalt, vanadium,titanium, rhodium, beryllium, gallium, selenium, and silver.
 2. Thecomposition of claim 1, wherein the modifying material of the secondlayer is bonded to a face of the BSSCO of the first layer, wherein theface is not substantially perpendicular to a c-axis of the BSSCO.
 3. Thecomposition of claim 1, wherein the modifying material of the secondlayer is bonded to a face of the BSSCO of the first layer, wherein theface is substantially perpendicular to any line in an “a-b” face of theBSSCO.
 4. The composition of claim 1, wherein the modifying material ofthe second layer is bonded to a face of the BSSCO of the first layer,wherein the face is substantially perpendicular to a b-axis of theBSSCO.
 5. The composition of claim 1, wherein the modifying material ofthe second layer is bonded to a face of the BSSCO of the first layer,wherein the face is substantially perpendicular to an a-axis of theBSSCO.
 6. The composition of claim 1, wherein the modifying material ofthe second layer is bonded to a face of the BSSCO of the first layer,wherein the face is substantially parallel to the c-axis.
 7. Thecomposition of claim 1, wherein the composition has improved operatingcharacteristics over those of BSSCO.
 8. The composition of claim 1,wherein the composition operates at a higher temperature than that ofBSSCO.
 9. The composition of claim 8, wherein the compositiondemonstrates extremely low resistance at a higher temperature than thatof BSSCO.
 10. The composition of claim 8, wherein the compositiontransitions from a non-ELR state to a ELR state at a temperature higherthan that of BSSCO.
 11. The composition of claim 1, wherein thecomposition has a transition temperature greater than that of BSSCO. 12.The composition of claim 8, wherein the composition operates at atemperature greater than any one of the following temperatures: 100K,150K, 200K, 250K, or 300K.
 13. The composition of claim 1, wherein thecomposition carries a greater amount of current in an ELR state thanthat carried by BSSCO in its ELR state.
 14. The composition of claim 1,wherein the second layer is deposited onto the first layer.
 15. Thecomposition of claim 1, wherein the first layer is deposited onto thesecond layer.
 16. The composition of claim 1, wherein the BSSCO of thefirst layer is formed on the second layer.
 17. A method comprising:bonding a modifying material to a face of BSSCO, wherein the modifyingmaterial comprises an element selected from the group consisting of:chromium, copper, bismuth, cobalt, vanadium, titanium, rhodium,beryllium, gallium, selenium, and silver.
 18. The method of claim 17,wherein the face of the BSSCO is not substantially perpendicular to ac-axis of the BSSCO.
 19. The method of claim 17, wherein bonding amodifying material to a face of BSSCO comprises depositing the modifyingmaterial onto the BSSCO.
 20. The method of claim 17, wherein bonding amodifying material to a face of BSSCO comprises forming the BSSCO on themodifying material.
 21. The method of claim 17, wherein bonding amodifying material to a face of BSSCO comprises bonding a first layercomprising the modifying material to a second layer comprising theBSSCO.
 22. A composition comprising: a first layer comprising BSSCO; anda second layer comprising a modifying material, wherein the modifyingmaterial of the second layer is bonded to the BSSCO of the first layer,wherein the modifying material is a conductive material that bondseasily with oxygen.
 23. The composition of claim 22, wherein themodifying material is an element selected from the group consisting of:chromium, copper, bismuth, cobalt, vanadium, titanium, rhodium,beryllium, gallium, selenium, and silver.
 24. A method comprising:bonding a modifying material to a face of an HTS perovskite material,wherein the HTS perovskite is BSSCO, wherein the modifying materialcomprises an element selected from the group consisting of: chromium,copper, bismuth, cobalt, vanadium, titanium, rhodium, beryllium,gallium, selenium, and silver.
 25. A composition comprising: a firstlayer comprising an extremely low resistance material, wherein theextremely low resistance material is BSSCO; a second layer comprising amodifying material, wherein the second layer is bonded to the firstlayer; a third layer comprising the extremely low resistance material;and a fourth layer of the modifying material, wherein the third layer isbonded to the fourth layer.